Direct Identification Research Articles

End-point diagnostics of Giardia duodenalis assemblages A and B by combining RPA with CRISPR/Cas12a from human fecal samples.

Giardia duodenalis is a common enteric protozoan parasite that is categorized into eight assemblages (A-H). In particular, assemblages A and B are zoonotic, capable of infecting both humans and animals worldwide, resulting in significant economic losses and public health challenges in epidemic regions. Thus, the development of rapid, accurate and non-laboratory-based diagnostic methods for infected animals is crucial for the effective prevention and control of giardiasis. Recent advancements in clustered, regularly interspaced, short palindromic repeats (CRISPR) and CRISPR-associated (Cas) protein (Cas12a) systems allow promising avenues for nucleic acid detection, characterized by their high flexibility, sensitivity and specificity. Combined recombinase polymerase amplification and CRISPR/Cas12a systems were combined and used as end-point diagnostic methods (termed REPORT) to detect G. duodenalis assemblage A and B. The diagnostic results can be observed by fluorescence readouts with the naked eye under blue light or colorimetric signals using a lateral flow strip (LFS). The limit of detection (LOD) of the REPORT‑based G. duodenalis assemblage A detection was 2.04 CFU/ml and 10 trophozoites per gram (TPG), and the LOD of assemblage B was 1.1 CFU/ml and 10 cysts per gram (CPG). The REPORT‑based G. duodenalis assemblage A and assemblage B detection methods have strong specificity and no cross-reactivity with other assemblages of G. duodenalis or common enteric parasitic protozoa and have excellent performance in clinical sample detection. This study presents a novel strategy for the direct identification of G. duodenalis assemblages A and B, requiring neither highly trained personnel nor costly specialized equipment.

A Systematic Workflow for Fragmentation Identification of Therapeutic Antibodies by Liquid Chromatography-Mass Spectrometry.

Fragmentation is a phenomenon ubiquitously observed during research and development of therapeutic antibodies. The clear identification of the cleavage site is vital for comprehending fragmentation mechanisms and optimizing processes. Capillary electrophoresis-sodium dodecyl sulfate (CE-SDS) is now widely used to detect and quantify fragments, while its peak identification is hindered by immature capillary electrophoresis-sodium dodecyl sulfate coupled with mass spectrometry techniques. In this study, we developed a systematic workflow for fragment characterization, which integrated direct identification, fragment enrichment, and fragmentation confirmation using multiple techniques, such as microscale peptide mapping (PM), PM of N-termini labeled sample, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in-gel extraction for molecular weight (MW) and PM measurements. By employing this innovative workflow, we successfully identified the cleavage sites of two therapeutic antibodies. In the first case, through direct liquid chromatography-mass spectrometry (LC-MS) characterization, the cleavages leading to the loss of biological function were identified on the linker of a bispecific antibody. In the second case involving a tetravalent antibody, direct LC-MS analysis failed. However, more sophisticated analysis nailed down the critical cleavage at the LC/HC: G105-R106 site in the CDR3 region of the antibody. Our systematic workflow provides a clear and accessible method for identifying cleavage sites with broad applicability across pharmaceutical laboratories.

Evaluation of the QIAstat-Dx BCID GN and GPF kits for direct identification and antimicrobial resistance prediction from blood culture bottles.

This is one of the first evaluations of the QIAstat BCID kit and demonstrates high levels of correlation for both identification and antimicrobial resistance prediction.

MiRNA-519e promotes cardiomyocyte cell division accompanied by pro-angiogenic and anti-apoptotic effects

Abstract Background MicroRNAs have the therapeutic potential for heart repair after myocardial infarction(MI). Using a functional high-throughput screening approach, we identified microRNA-519e(miR-519e) as an inducer of cell-cycling in human-derived iPSC-cardiomyocytes(hiPSC-­CM). Purpose This study examines miR-519e for cell division in hiPSC-­CM, additional beneficial functions in heart-related non-CMs, and direct target identification and validation in vitro and in vivo. Methods MiR-519e-mimics or miR-scrambled(miR-scr) were transfected into hiPSC-­CM, human aortic endothelial cells(HAEC) and human cardiac fibroblasts(cFB). Proliferative markers (EdU(5-Ethynyl-2'- deoxyuridine), H3P(Phospho-Histone H3) and AURKB(Aurora B-kinase)) and apoptotic response using MTT assay after exposure to doxorubicin were assessed in hiPSC­-CMs. Angiogenic capacity of HAEC was evaluated by tube formation assay and fibrotic response of cFBs using EdU and α-SMA(smooth muscle actin) staining. In vivo, a mouse MI model with ligation of the left anterior descending followed by intramyocardial injection of miR-519e or miR-scr was used. Direct target identification of miR-519e was assessed using in silico analysis combined with RNA-Seq of miR-519e-mimic treated hiPSC-CMs and validated using Ago2-RNA immunoprecipitation(RIP) followed by qPCR. Results After transfection of miR-519e-mimics in hiPSC-­CM, a significant proliferative response indicative of cell division was observed in immunofluorescence staining and on protein level as compared with miR-scr treated hiPSC-CMs (EdU, H3P and AURKB, p<0.01). Apoptosis was blunted in miR-519e-treated hiPSC-CMs (p<0.05). MiR-519e-treatment of HAEC resulted in more meshes (p<0.01) and longer tube length (p<0.05), indicating enhanced pro-angiogenic capacity. Importantly, EdU-uptake and α-SMA were similar in miR-519e-treated cFB as compared to miR-scr, suggesting neutral effects of miR-519e on myofibroblast transition. In mice undergoing MI, injection of miR-519e-mimics significantly downregulated CDKN1A/P21(Cyclin dependent kinase inhibitor 1A) (p<0.05 vs. miR-scr), a direct target of miR-519e and negative master regulator of cell-cycling. For further novel target identification of miR-519e, we performed in silico analysis combined with RNA-Seq data from miR-519e-treated hiPSC-CM and validation using Ago2-RIP followed by qPCR. Herein, we identified PTEN(Phosphatase and tensin homolog) and TGFBR2(Transforming growth factor β receptor 2) that are involved in cardiomyocyte proliferation and hypoxic response, as direct targets of miR-519e. Conclusion Collectively, miR-519e is a potent inducer of cell division in human cardiomyocytes, with anti-apoptotic and pro-angiogenic capacity in the absence of pro-fibrotic effects. We show that miR-519e treatment downregulates key negative cell-cycle regulators in vivo and we identified novel direct targets of miR-519e that are involved in regulatory pathways for heart regeneration.

Accuracy of various matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based rapid identification methods—As a tool to augment diagnostic stewardship in blood culture laboratory, South India

BackgroundBlood stream infection is a medical emergency associated with high morbidity and mortality. Prompt identification of bloodstream infection-causing microorganisms directly from positive blood culture will significantly enhance patient care by reducing the turnaround time of pathogen recognition. MethodsA total of 256 freshly flagged positive blood culture bottles were subjected to Gram staining. Direct MALDI-TOF MS analysis was performed following sample preparation techniques such as lysis centrifugation, lysis filtration and VITEK® MS BC kit to directly identify microorganisms from positive blood cultures. Along with these short-term incubation methods of Choco spot and minute colony(8–10h) were also performed. All those positive bottles were identified by the routine (reference) laboratory method. Results177 isolates (69.14 %) were correctly identified by Lysis centrifugation, 163 isolates (63.67 %) were correctly identified by Lysis filtration, 206 isolates (80.47 %) were correctly identified by Choco spot,250 isolates (97.65 %) were correctly identified from minute colony (8–10h) of incubation. Of 162 isolates,115 isolates (70.99 %) were correctly identified by VITEK® MS Blood culture kit, (BioMérieux). VITEK® MS BC kit method revealed higher agreement with the kappa value of 0.697 than lysis centrifugation (0.672) followed by lysis filtration (0.611). ConclusionsIn house method of lysis centrifugation is found to be equivalent to VITEK® MS BC kit method and superior to lysis filtration method in correct direct identification of bacteria from positive blood cultures by MALDI-TOF MS analysis. As lysis centrifugation requires only 10 min of processing time as compared to overnight incubation, thus it offers a less expensive substitute for the VITEK® MS BC kit in the clinical laboratory. As a consequence of this study, we have implemented direct MALDI-TOF-based identification from positive BCs in our daily routine diagnostic management.

Visualization of the Distance-Dependent Synergistic Interaction in Heterogeneous Dual-Site Catalysis.

Understanding the characteristics of interfacial hydroxyl (OH) at the solid/liquid electrochemical interface is crucial for deciphering synergistic catalysis. However, it remains challenging to elucidate the influences of spatial distance between interfacial OH and neighboring reactants on reaction kinetics at the atomic level. Herein, we visualize the distance-dependent synergistic interaction in heterogeneous dual-site catalysis by using ex-situ infrared nanospectroscopy and in situ infrared spectroscopy techniques. These spectroscopic techniques achieve direct identification of the spatial distribution of synergistic species and reveal that OH facilitates the reactant deprotonation process depending on site distances in dual-site catalysts. Via modulating Ir-Co pair distances, we find that the dynamic equilibrium between generation and consumption of OH accounts for high-efficiency synergism at the optimized distance of 7.9 Å. At farther or shorter distances, spatial inaccessibility and resistance of OH with intermediates lead to OH accumulation, thereby diminishing the synergistic effect. Hence, a volcano-shaped curve has been established between the spatial distance and mass activity using formic acid oxidation as the probe reaction. This notion could also be extended to oxophilic metals, like Ir-Ru pairs, where volcano curves and dynamic equilibrium further evidence the universal significance of spatial distances.

Longitudinal Assessment of Nasopharyngeal Biomarkers Post-COVID-19: Unveiling Persistent Markers and Severity Correlations.

SARS-CoV-19 infection provokes a variety of symptoms; most patients present mild/moderate symptoms, whereas a small proportion of patients progress to severe illness with multiorgan failure accompanied by metabolic disturbances requiring ICU-level care. Given the importance of the disease, researchers focused on identifying severity-associated biomarkers in infected patients as well as markers associated with patients suffering long-COVID. However, little is known about the presence of biomarkers that remain a few years after SARS-CoV-2 infection once the patients fully recover of the symptoms. In this study, we evaluated the presence of persistent biomarkers in the nasopharyngeal tract two years after SARS-Cov-2 infection in fully asymptomatic patients, taking into account the severity of their infection (mild/moderate and severe infections). In addition to the direct identification of several components of the Coronavirus Infection Pathway in those individuals that suffered severe infections, we describe herein 371 proteins and their associated canonical pathways that define the different adverse effects of SARS-CoV-2 infections. The persistence of these biomarkers for up to two years after infection, along with their ability to distinguish the severity of the infection endured, highlights the surprising presence of persistent nasopharyngeal exudate changes in fully recovered patients.

Identification of novel and potent inhibitors of SARS-CoV-2 main protease from DNA-encoded chemical libraries.

In vitro screening of large compound libraries with automated high-throughput screening is expensive and time-consuming and requires dedicated infrastructures. Conversely, the selection of DNA-encoded chemical libraries (DECLs) can be rapidly performed with routine equipment available in most laboratories. In this study, we identified novel inhibitors of SARS-CoV-2 main protease (Mpro) through the affinity-based selection of the DELopen library (open access for academics), containing 4.2 billion compounds. The identified inhibitors were peptide-like compounds containing an N-terminal electrophilic group able to form a covalent bond with the nucleophilic Cys145 of Mpro, as confirmed by x-ray crystallography. This DECL selection campaign enabled the discovery of the unoptimized compound SLL11 (IC50 = 30 nM), proving that the rapid exploration of large chemical spaces enabled by DECL technology allows for the direct identification of potent inhibitors avoiding several rounds of iterative medicinal chemistry. As demonstrated further by x-ray crystallography, SLL11 was found to adopt a highly unique U-shaped binding conformation, which allows the N-terminal electrophilic group to loop back to the S1' subsite while the C-terminal amino acid sits in the S1 subsite. MP1, a close analog of SLL11, showed antiviral activity against SARS-CoV-2 in the low micromolar range when tested in Caco-2 and Calu-3 (EC50 = 2.3 µM) cell lines. As peptide-like compounds can suffer from low cell permeability and metabolic stability, the cyclization of the compounds will be explored in the future to improve their antiviral activity.

Direct Identification of the Continuous Relaxation Time and Frequency Spectra of Viscoelastic Materials

Relaxation time and frequency spectra are not directly available by measurement. To determine them, an ill-posed inverse problem must be solved based on relaxation stress or oscillatory shear relaxation data. Therefore, the quality of spectra models has only been assessed indirectly by examining the fit of the experiment data to the relaxation modulus or dynamic moduli models. As the measures of data fitting, the mean sum of the moduli square errors were usually used, the minimization of which was an essential step of the identification algorithms. The aim of this paper was to determine a relaxation spectrum model that best approximates the real unknown spectrum in a direct manner. It was assumed that discrete-time noise-corrupted measurements of a relaxation modulus obtained in the stress relaxation experiment are available for identification. A modified relaxation frequency spectrum was defined as a quotient of the real relaxation spectrum and relaxation frequency and expanded into a series of linearly independent exponential functions that are known to constitute a basis of the space of square-integrable functions. The spectrum model, given by a finite series of these basis functions, was assumed. An integral-square error between the real unknown modified spectrum and the spectrum model was taken as a measure of the model quality. This index was proved to be expressed in terms of the measurable relaxation modulus at uniquely defined sampling instants. Next, an empirical identification index was introduced in which the values of the real relaxation modulus are replaced by their noisy measurements. The identification consists of determining the spectrum model that minimizes this empirical index. Tikhonov regularization was applied to guarantee model smoothness and noise robustness. A simple analytical formula was derived to calculate the optimal model parameters and expressed in terms of the singular value decomposition. A complete identification algorithm was developed. The analysis of the model smoothness and model accuracy for noisy measurements was carried out. The equivalence of the direct identification of the relaxation frequency and time spectra has been demonstrated when the time spectrum is modeled by a series of functions given by the product of the relaxation frequency and its exponential function. The direct identification concept can be applied to both viscoelastic fluids and solids; however, some limitations to its applicability have been pointed out. Numerical studies have shown that the proposed identification algorithm can be successfully used to identify Gaussian-like and Kohlrausch–Williams–Watt relaxation spectra. The applicability of this approach to determining other commonly used classes of relaxation spectra was also examined.

Impact of direct identification of bacteria in blood culture–positive specimens by matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry on physician selection of antimicrobial therapy

BackgroundRapid identification of the causative organism in blood stream infections is essential for early initiation of appropriate antimicrobial therapy. Direct identification of bacteria in positive blood culture bottles using matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry is a promising application. A variety of direct identification methods have been reported; however, few studies have evaluated the impact of these methods on physician decision making regarding antimicrobial therapy. MethodsWe developed a simple method for direct bacterial identification and applied it to daily clinical practice to investigate the impact of direct identification of bacteria in positive blood culture bottles on physicians’ choice of antimicrobial agents for treatment. ResultsFrom January 2016 to December 2022, we attempted direct identification in 98 cases and successfully acquired identification results in 88 cases. In three cases, no empiric antimicrobial agents were initiated at the time of venipuncture for blood culture but later initiated based on the direct identification results. In the remaining 85 cases, empiric antimicrobial therapy was initiated at the time blood cultures were performed, and in 29 cases, empiric antimicrobial therapy was changed after direct identification. In 17 of these 29 cases, the antimicrobial therapy was changed based on the direct identification of bacterial genus/species, resulting in a change to an effective antimicrobial therapy before the antimicrobial susceptibility testing results were available. ConclusionsDirect identification of bacteria from positive blood culture bottles could contribute to earlier selection of or changes to antimicrobial therapies by attending physicians.

Development of methodology for the visual identification of Tributyltin (TBT) in antifouling paint matrices.

Organotin compounds (OTC), mainly tributyltin (TBT), have been used since the 1970s as biocides in the composition of antifouling paints. Due to its physical-chemical characteristics, TBT has high toxicity to the marine environment affecting non-target organisms. The present study aims to develop a method of direct visual identification of TBT in antifouling paints using the cyclopalladate complex, 4- (2-thiazolylazo) resorcinol (TAR-Pd), synthesized in our laboratory. Tests were performed in blank and in the paint matrix with the following OTC: TBT-O; TBT-Cl; TPT-Cl; DBT-Cl (tributyltin oxide, tributyltin chloride, triphenyltin chloride, dibutyltin chloride), in addition to the SnCl4 and SnCl2 compounds (tin IV chloride and tin II chloride), all at a concentration of approximately 20g/ kg of dry paint). The test was performed by applying paint samples to test bodies and scraping a few tens of milligrams of the dry paint film. The scraped paint samples were submitted to the test, showing a different staining reaction for the TBT-Cl and SnCl4 samples concerning blank and other samples (TBT-O, TPT, DBT-Cl, and SnCl2). Solution tests were performed to characterize reaction products by spectroscopy in the visible band. The method developed has potential for application in real samples, being selective for TBT-Cl and SnCl4 in an acid medium, obtaining a limit of detection, in the range of 1-10mg/kg dry paint.

Direct Identification of O─O Bond Formation Through Three‐Step Oxidation During Water Splitting by Operando Soft X‐ray Absorption Spectroscopy (Adv. Sci. 40/2024)

Direct Identification of O─O Bond Formation Through Three‐Step Oxidation During Water Splitting by Operando Soft X‐ray Absorption Spectroscopy (Adv. Sci. 40/2024)

Explainable breast cancer molecular expression prediction using multi-task deep-learning based on 3D whole breast ultrasound

ObjectivesTo noninvasively estimate three breast cancer biomarkers, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) and enhance performance and interpretability via multi-task deep learning.MethodsThe study included 388 breast cancer patients who received the 3D whole breast ultrasound system (3DWBUS) examinations at Xijing Hospital between October 2020 and September 2021. Two predictive models, a single-task and a multi-task, were developed; the former predicts biomarker expression, while the latter combines tumor segmentation with biomarker prediction to enhance interpretability. Performance evaluation included individual and overall prediction metrics, and Delong’s test was used for performance comparison. The models’ attention regions were visualized using Grad-CAM + + technology.ResultsAll patients were randomly split into a training set (n = 240, 62%), a validation set (n = 60, 15%), and a test set (n = 88, 23%). In the individual evaluation of ER, PR, and HER2 expression prediction, the single-task and multi-task models achieved respective AUCs of 0.809 and 0.735 for ER, 0.688 and 0.767 for PR, and 0.626 and 0.697 for HER2, as observed in the test set. In the overall evaluation, the multi-task model demonstrated superior performance in the test set, achieving a higher macro AUC of 0.733, in contrast to 0.708 for the single-task model. The Grad-CAM + + method revealed that the multi-task model exhibited a stronger focus on diseased tissue areas, improving the interpretability of how the model worked.ConclusionBoth models demonstrated impressive performance, with the multi-task model excelling in accuracy and offering improved interpretability on noninvasive 3DWBUS images using Grad-CAM + + technology.Critical relevance statementThe multi-task deep learning model exhibits effective prediction for breast cancer biomarkers, offering direct biomarker identification and improved clinical interpretability, potentially boosting the efficiency of targeted drug screening.Key PointsTumoral biomarkers are paramount for determining breast cancer treatment.The multi-task model can improve prediction performance, and improve interpretability in clinical practice.The 3D whole breast ultrasound system-based deep learning models excelled in predicting breast cancer biomarkers.Graphical

Dental Identification System in Public Health: Innovations and Ethical Challenges: A Narrative Review.

Dental identification systems (DISs) encompass various techniques used for forensic identification, serving as alternatives or complements to genetic methods. Technologies such as microchip implants, prosthetic inscriptions, microSD cards, and identification plaques have been proposed to address limitations in comparative methods, offering streamlined processes for forensic experts. This study reviews current and potential DIS implementations, emphasizing cost-effectiveness and community benefits. Literature analysis from PubMed (2008-2024) yielded 17 relevant articles on implantable DISs, enabling direct subject identification via teeth or prostheses. The integration of DIS aims to enhance accuracy and speed in personal profiling and legal identification, promoting technology transfer in dentistry. It will be necessary to develop strict privacy regulations to protect patient data and establish ethical guidelines for their use. The study's aim is to highlight that the universal adoption of DISs could mitigate healthcare disputes and facilitate data exchange in clinical settings, which is particularly beneficial for vulnerable populations.

A Comparative Study of Bacteriological Profile and Susceptibility Pattern by Rapid Direct Manual Identification and Antimicrobial Susceptibility Testing with Routine Blood Culture Method in Neonatal Septicemia.

A Comparative Study of Bacteriological Profile and Susceptibility Pattern by Rapid Direct Manual Identification and Antimicrobial Susceptibility Testing with Routine Blood Culture Method in Neonatal Septicemia.

Scywalker: scalable end-to-end data analysis workflow for long-read single-cell transcriptome sequencing.

Existing nanopore single-cell data analysis tools showed severe limitations in handling current data sizes. We introduce scywalker, an innovative and scalable package developed to comprehensively analyze long-read sequencing data of full-length single-cell or single-nuclei cDNA. We developed novel scalable methods for cell barcode demultiplexing and single-cell isoform calling and quantification and incorporated these in an easily deployable package. Scywalker streamlines the entire analysis process, from sequenced fragments in FASTQ format to demultiplexed pseudobulk isoform counts, into a single command suitable for execution on either server or cluster. Scywalker includes data quality control, cell type identification, and an interactive report. Assessment of datasets from the human brain, Arabidopsis leaves, and previously benchmarked data from mixed cell lines demonstrate excellent correlation with short-read analyses at both the cell-barcoding and gene quantification levels. At the isoform level, we show that scywalker facilitates the direct identification of cell-type-specific expression of novel isoforms. Scywalker is available on github.com/derijkp/scywalker under the GNU General Public License (GPL) and at https://zenodo.org/records/13359438/files/scywalker-0.108.0-Linux-x86_64.tar.gz.

Ecotoxicological assessment of sanitary sewer overflows and rainfall dynamics offers insights into conditions for potential adverse ecological outcomes

Sewer overflows are an environmental concern due to their potential to introduce contaminants that can adversely affect downstream aquatic ecosystems. As these overflows can occur during rainfall events, the influence of rainwater ingress from inflow and infiltration on raw untreated wastewater (influent) within the sewer is a critical factor influencing the dilution and toxicity of the contaminants. The Vineyard sewer carrier in the greater city of Sydney, Australia, was selected for an ecotoxicological investigation of a sanitary (separate from stormwater) sewerage system and a wet-weather overflow (WWO). Three influent samples were collected representing dry-weather (DW), intermediate wet-weather (IWW) and wet-weather (WW). In addition, a receiving water sample was also collected downstream in Vineyard Creek (WW-DS) coinciding with a WWO.We employed direct toxicity assessment (DTA) and toxicity identification evaluation (TIE) approaches to gain comprehensive insights into the nature and magnitude of the impact on influent from rainwater ingress into the sewer. Three standard ecotoxicological model species, a microalga, Chlorella vulgaris, the water flea, Ceriodaphnia dubia and the midge larva, Chironomus tepperi were used for both acute and chronic tests. The study revealed variable toxicity responses, with the sample of influent collected in wet-weather displaying lower toxicity compared to the dry-weather sample of influent. Ammonia, and metals, were identified in dry weather as contributors to the observed toxicity, however, this risk was alleviated through rainwater ingress in wet-weather with further dilution within the receiving water. Based on toxicity data, dilutions of influent to minimise effects on C. vulgaris and C. dubia ranged from 1 in 12 in DW to 1 in 2.8 in WW, and further diminished in the receiving water to 1 in 1.8. The successful application of ecotoxicological approaches enabled the assessment of cumulative effects of contaminants in influent, offering valuable insights into the sanitary sewer system under rainwater ingress.

Discovery of Thioether-Cyclized Macrocyclic Covalent Inhibitors by mRNA Display.

Macrocyclic peptides are promising scaffolds for the covalent ligand discovery. However, platforms enabling the direct identification of covalent macrocyclic ligands in a high-throughput manner are limited. In this study, we present an mRNA display platform allowing selection of covalent macrocyclic inhibitors using 1,3-dibromoacetone-vinyl sulfone (DBA-VS). Testcase selections on TEV protease resulted in potent covalent inhibitors with diverse cyclic structures, among which cTEV6-2, a macrocyclic peptide with a unique C-terminal cyclization, emerged as the most potent covalent inhibitor of TEV protease described to-date. This study outlines the workflow for integrating chemical functionalization─installation of a covalent warhead─with mRNA display and showcases its application in targeted covalent ligand discovery.

The potential of aptamers for the analysis of ceramic bound proteins found within pottery

Archaeological pottery are the most numerous objects found during excavations and reflect the culinary practices of the past. However, their functionality for cooking/storing specific foods or drinks cannot be deduced solely from comparing their shapes and sizes. Analysis of protein residues bound to ceramics can reveal the protein/animal type through their amino acid sequence, thus enabling direct identification of food types. Therefore, the aim of our experimental study was to test sixteen aptamers for the analysis of proteinaceous organic residues found within the porous structure of pottery. Traditionally prepared archaeological ceramic replicas were cooked for 5 days in various food/protein suspensions, were UV aged, buried for a year, excavated, and extensively cleaned. Their shards were analysed using immunofluorescence microscopy with aptamers. Results show that eight aptamers (Clone1 and Kirby for egg residuals; seqU5 and BLG14 for milk residuals; HA for blood residuals; Gli4 for gluten residuals; Par1 for fish residuals; and D1 for collagen residuals) produced a successful/specific immunofluorescence microscopy result when they were hybridised to shards containing target protein residuals. Interestingly, on whole egg control samples, when the egg lysozyme-targeting aptamer Kirby was used, fluorescence intensity was 3.1 times greater compared to that observed with anti-ovalbumin antibodies.

Spin‐State Switching of Spin‐Crossover Complexes on Cu(111) Evidenced by Spin‐Flip Spectroscopy

Spin‐crossover compounds can be switched between two stable states with different magnetic moments, conformations, electronic, and optical properties, which opens appealing perspectives for technological applications including miniaturization down to the scale of single molecules. Although control of the spin states is crucial their direct identification is challenging in single‐molecule experiments. Here we investigate the spin‐crossover complex [Fe(HB(1,2,4‐triazol‐1‐yl)3)2] on a Cu(111) surface with scanning tunneling microscopy and density functional theory calculations. Spin crossover of single molecules in dense islands is achieved via electron injection. Spin‐flip excitations are resolved in scanning tunneling spectra in a magnetic field enabling the direct identification of the molecular spin state, and revealing the existence of magnetic anisotropy in the HS molecules.